For more than 30 years, Zalco Laboratories has provided gas composition analysis for petroleum and natural gas systems, refineries, and more recently landfill/digester gas. They provide LFG testing for a number of compounds, including CH4-C10 hydrocarbons, CO2, CO, O2, N2, total sulfur/H2S, NMOCs; and also determine gross heating value (Btu/ft3).